In this film we find many of Jean-Mocky's recurring themes, present in many of his films, either as main subjects or underlying the plot. Among them: the provincial bourgeoisie, contemptuous and haughty, the mediocre narcissism of the Church, the sexual greed of all. In the context of a detective film. A pre-teen girl is found killed and raped. She was the model of Alberto Sordi, a painter who is restoring a painting in the local church. He is unwillingly accused, as he was the last one to see her. The film is also a plea against the death penalty. He is the witness of the title and will find himself accused of rape and murder. Philippe Noiret plays a contemptuous bourgeois, and his wife and the provincial bourgeoisie even more so.
A vitriolic portrait of mediocrity and caste racism, Jean-Pierre Mocky hits hard (the original material is a novel by Norman Daniels) with this film that slaps the viewer in the face. And he benefits from an important cast, with Philippe Noiret who excels as a concupiscent monster who can't help it, Alberto Sordi as a very stupid naïf, and Roland Dubillard in the role of the commissioner who gloats about annoying this bourgeoisie who believes itself untouchable.